Constellation, le dépôt institutionnel de l'Université du Québec à Chicoutimi

Résumé

Handheld XRF (HHXRF) is an analytical tool often used for chemical characterization, environmental analysis or mineral exploration. However, few studies deal with its potential use as a quality control instrument within an industrial context, such as mineral processing or transformation. Quartz is an ideal test material; it is a simple matrix allowing for better isolation of different parameters including detection limits, precision and accuracy, instrumental drift, surface representativeness and sample preparation. In this study, we determined that the specific limit of detection was lower than 70 μg/g for TiO2, Fe2O3 and CaO. The HHXRF analyzed pressed pellets of matrix-matched reference materials. Estimates for TiO2, Fe2O3 and CaO were similar to certified values, while estimates for low concentration light elements (Al2O3 and MgO) were less accurate. For faster and higher throughput, as often required in an industrial context, HHXRF can be used directly on mineral sample without sample preparation. Five in-situ determinations on a 10-cm-sided block of quartz, produced an accuracy acceptable for industrial needs. However, in-situ determinations are limited by the flatness of the analytical surface, and minute accessory phases can induce some erratic results. Our tests suggest, however, that HHXRF is generally suitable for the control quality of quartz in an industrial context.